The present invention relates generally to energy management techniques. More particularly, the present invention provides a method and system for isolating local area networks over at least a co-axial wiring for energy management, but it can be applied to many other applications.
As larger universities and research labs obtained more computers during the late 1960s, increasing pressure mounted to provide high-speed interconnections to share information across a common network, often referred to as a Local Area Network (LAN). The development and proliferation of DOS-based personal computers from the early 1980's and the introduction of the World-Wide Web (WWW), which enabled the spread of information over the Internet through an easy-to-use and flexible format, popularized the adoption of home networking. A home network is a residential LAN, and is used to connect multiple devices within the home. More recently Internet Service Providers (ISP) such as AT&T and British Telecom have been using home networking to provide triple play services (voice, video and data) to customers.
Early LAN cabling used for LAN had always been based on various grades of co-axial cable, but IBM's Token Ring used shielded twisted pair cabling of their own design, and in about 1984 StarLAN showed the potential of simple CAT3 unshielded twisted pair—the same simple cable used for telephone systems. This led to the development of 10Base-T (and its successors) and structured cabling which is still the basis of most LANs today. Structural cabling is most cost efficient in new facilities but it becomes technically challenging and cost prohibitive in existing facilities. Given that the majority of buildings are existing and new buildings are just a small percentage of the overall market, other technologies were developed that transmit data either over the air or through the use of existing wiring.
As new applications such as Internet Protocol Television (IPTV)—a system where a digital television service is delivered using Internet Protocol over a network infrastructure, which may include delivery by a broadband connection, and Video of Demand (VoD)—a system that either stream content through a set-top box, allowing viewing in real time, or download it to a device such as a computer, digital video recorder, personal video recorder or portable media player for viewing at any time, matures, the bandwidth requirement for a LAN will need to be increased to be able to support these applications.
Wireless 802.11 technologies are limited in bandwidth, coverage, interferences and security. Other network technologies that use the existing wiring of a facility such as HomePNA Phoneline and HomePlug™ Powerline uses bare copper wires which are easily susceptible to interferences and they are also limited by its shared medium; thus, making it extremely challenging to deploy bundled applications and services. A co-axial wire is a cable consisting of an inner conductor, surrounded by a tubular insulating layer typically made from a flexible material with a high dielectric constant, all of which is then surrounded by another conductive layer (typically of fine woven wire for flexibility, or of a thin metallic foil), and then finally covered again with a thin insulating layer on the outside—making it the most ideal network infrastructure for high-bandwidth applications that is part of the existing wiring of a facility.
Although highly successful, networking techniques have not been used successfully in energy management applications. That is, energy management applications have been crude and often difficult to use in an easy and convenient manner. Energy management applications are also non-existent in some areas. These and other limitations of conventional energy management techniques have been described throughout the present specification and more particularly below.
From the above, it is seen that improved techniques are desired to improve use of existing co-axial wiring for LAN and in particularly energy management applications.